For a long time has visual effects been used in movies, video games and other recorded or non-live entertainment material. Visual effects may be used to create imaginary events. Lately, there has been some development for producing visual effects for live performances, such as theater and illusion shows, as well. However, the effects that can be generated by these arrangements fall far behind the ones audiences are accustomed to see in TV and movies.
Projectors may be used in theater settings to project images or videos on the back wall, creating changing scenery, for example. A different set of lighting is also normally used in live shows to create some visual effects. For example, light settings can be used to change the atmosphere by dimming and brightening different parts of the stage area. Spotlights are also commonly used to highlight areas or actors. Some spotlight arrangements may even have the function to follow actors moving on the stage.
Amongst other deficits, prior art solutions for live performances have problems with timing and accuracy. The known arrangements are not capable of keeping up with moving objects in real-time. Projectors or light settings set to follow a moving object, such as an actor on stage, tend to be for the human eye some fractions behind the target. This is both annoying for the audience, but also restricts performers of creating more outstanding show experiences. Performances requiring exact timing, such as illusion tricks, lose their significance without real-time effects. With known arrangements it's especially difficult to create visual effects on randomly moving objects, such as actors on stage, whose distance between the projecting unit changes constantly.
Projected images and videos with conventional projectors tend to need a flat surface such as a screen for the audience to be able to view the projections properly. The known arrangements will also need a close projecting range for the projections to stay sharp. This will set some restrictions on the mounting of the projector and the design of the space.